Elon Musk’s rocket and satellite giant is already planning a stock sale at an $800 billion valuation. Going public could put it in the trillion-dollar club.

© Meridith Kohut for The New York Times

A sale of insider shares at $421 a share would make Mr. Musk’s rocket company the most valuable private company in the world, as it readies for a possible initial public offering next year.

© Meridith Kohut for The New York Times

As NASA worries that China will win the next moon race, Elon Musk and his company tangled with critics.